1. Technical Field
The present invention generally relates to lifting devices. More particularly, the present invention relates to vehicle lifting devices. Even more particularly, the present invention relates to vehicle lifting devices which are easily and readily convertible between a frame engaging lift to a wheel engaging lift, and vice versa.
2. Background Information
There are numerous devices available on the market today for lifting vehicles off the ground so that maintenance and service can be performed thereon. In addition to traditional in-ground vehicle lifts, other common lifts include above-ground frame engaging lifts and above-ground mobile column wheel engaging lifts.
Conventional frame engaging vehicle lifts include two vertically oriented posts or support columns, wherein each post includes a pair of arms which extend horizontally therefrom. At the free end of each of the arms is a frame contact pad for engagement to the underside of the vehicle for support thereof. Positioning of the lift arms can be achieved not only by longitudinally extending or retracting the telescoping tubes which form the lift arms, but also by swinging the arms about a substantially vertical pivot point. In accordance with this structure, the contact pads can be strategically engaged to locations on the underside of the vehicles, thus facilitating lifting and preventing vehicle damage. Once the vehicles are lifted, the desired maintenance and service tasks can be performed. For more information regarding the construction and operation of high quality above-ground frame engaging vehicle lifts, refer to the 20-page booklet of the assignee of the present invention, Mohawk Resources Ltd., PO Box 110, Mohawk Industrial Park, Amsterdam, N.Y., entitled, "What Makes a Mohawk a Mohawk," the disclosure of which is hereby incorporated by reference in its entirety. Moreover, further information regarding Mohawk Resources Ltd. frame engaging lifts can be found in the following product literature: Model A-7 (7,000-lb asymmetric lift) (Rev. 9/96), Model System 1 (9,000-lb clear floor lift) (Rev. 9/94), and Models LMF-12 & TP-15 (12,000 & 15,000-lb capacity lifts) (Rev. 9/94), all of which are expressly incorporated by reference in their entireties.
However, electric vehicles pose significant frame access problems for conventional frame contacting lifts because of large and bulky battery and external storage packs which are attached to the underside of such vehicles. Other alternate fuel vehicles, such as natural gas and propane vehicles, also present the same frame access problems. Therefore, above-ground frame engaging vehicle lifts are generally not properly adapted for use with alternate fuel vehicles. Also, another problem associated with above-ground frame engaging vehicle lifts is the timely setup required to properly engage the contact pads to the underside of the vehicles.
An alternative to above-ground frame engaging lifts--suitable to safely handle alternate fuel vehicles--are above-ground mobile column wheel engaging lifts. However, mobile column lifts require a post or column for each wheel of the vehicle. Therefore, if the vehicle includes four wheels, four separate posts are required. In order to employ such a wheel engaging lift, each post is moved on the shop floor and positioned next to a corresponding wheel of a vehicle. After the four posts are positioned and the corresponding wheels engaged, the vehicle can be lifted so that maintenance and repair can be performed. Yet, because four posts are generally required in such systems, the downside is added cost and the need for additional floor space. Moreover, because four posts are usually required, these systems are more prone to malfunction, thereby resulting in increased maintenance costs.
Thus, a need exists for a wheel engaging vehicle lift which contains a solution to all of the aforementioned problems.